Compressor



c. F. NYSTROM COMPRESSOR Filed 00%. 12,1952

March 20, 1934.

2 Sheets-Sheet 1 INVENTOR C RE)... F. Nvs'r ROM BY n, ATTORNEY WITNESSES: 5 to:

March 20, 1934.

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\ 051? ATTORNEY Patented Mar.- 20, 1934 UNITED STATES PATENT OFFICE COMPRESSOR Carl F. Nystrom, Springfield, Masa, assignor' to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application October 12, 1932, Serial No. 637,512 8 Claims. 01. 230- 238) My invention relates to compressors and particularly to a device for adjusting the head clear-' thereby iswithin small limits and cannot be progressively varied without changing the thickness of the gasket, which entails removing and replacing the compressor head. Changing the compressor stroke is disadvantageous because the compressor is usually designed to operate at a predetermined stroke and any change therein impairs the volumetric efiiciency of the compressor.

My improved device for adjusting head clearances of reciprocating compressors differs from so the usual means and provides for adjusting the disposition of the cylinder block of the compressor byan eccentric adjusting device, whereby the entire cylinder block, with the head attached thereto, has its distance varied progressively by small magnitudeswith respect to the fixed axis of the eccentric piston reciprocating means, which fixed axis is usually thecompres-v sor drive shaft. 4 It is an object of my invention, therefore, to do away with such head clearance adjusting means for compressors as head gaskets and stroke changing devices, and-to provide an adjustment by varying the distance of the entire cylinder progressive variable adjustments by small magni-' tudes over a considerable range.

It isa further object of my invention to provide an inexpensive and easily operable device fcr adjusting the head clearance of a compressor. It is still a further object of my invention to provide a cylinder head adjusting device which is adaptable for use with single or multiple cylinder reciprocating compressors. I

These and other objects are effected. bymy invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, in which:

Fig. 1 is a view of a portion of a compressor 5 and illustrates a compressor head adjusting shown) means as constructed and arranged in one embodiment of my invention;

Fig. 2 is an enlarged view of the adjusting device taken on line 11-11 of Fig. 1;

Fig. 3 is an enlarged perspective view of an 60 eccentric bushing utilized in the embodiments of my invention shown in Figs. 1 and 5;

, Fig. 4 is an end view of a two cylinder compressor and illustrates a second' embodiment of my cylinder head adjusting device; and,

Fig. 5 is a view of the two cylinder compressor taken on line VV of Fig. 4.

Although I have shown my adjusting device as applied to a specific type of compressor, it is understood that I do not wish to be limited there by except as set forth in the appended claims.

Referring specifically to the drawings for a detailed description of the first. embodiment of my invention shown in Figs. 1 to 3, numeral-1 designates generally a compressor of the single 7 cylinder type which is contained in a casing 2 and which is supported by a web or frame 3. The web 3 also provides a bearing 4 for a shaft 5 through which power from a suitable source (not shown) is transmitted for actuating the compressor. 1.

The compressor 1 specifically'conlprises a cylinder 6 contained in\a cylinder block 'Zand a reciprocating piston 8. A head 9 is attached to the cylinder block 7 by any suitable means (not A connecting rod 10 having a crank bearing 11 on one end thereof is attached to the piston 8 by any well-known means. Eccentric means 12 comprising a mass 13 and a crank pin 14 eccentric to the aids of the shaft 5 are attached to the'shaft, and the crank'pin 14 and crank bearing 11 cooperate to reciprocate the piston 8 in the cylinder 6 when turning movement is imparted to the shaft 5.

Turning now-toa description of the cylinder 1 head adjusting means, a cylindrical dowel pin 15-is preferably formed integrally with the cylinder block, and a cylindrical housing for the dowel pin 15 is formed by providing an opening 16 in the web or frame 3, the opening being parallel to the shaft bearing axis. The opening 16 is slightly and outer surfaces 18 and 19, respectively, but

the inner surfaceis eccentric to theaxis of the inder block '7 are slightly larger in diameter than the bolts 21 fora purpose hereinafter described.

In order to adjust the head clearance of the compressor 1, the bolts 21 are left loose or loosened so that the cylinder block '7 is not. clamped tightly to the web 3. The eccentric bushing 17,

fitting the dowel pin 15 and the cylindrical opening 16 in the frame, is turned in order to move the cylinder structure 7 toward or away from the axis of the shaft 5 to secure a desired clearance volume. The cylinder block 7 may move in any direction because of the enlarged apertures 22 for the clamping bolts 21.

When the desired clearance between the piston 8 and head 9 is obtained by any suitable measuringdevice, one of the fingers 20a of the bushing 17 is bent, as shown in Figs. 1 and 2, to engage in the recess 23 formed in the cylinder structure to hold the bushing in the desired position of adjustment. The bolts 21 are then drawn up to clamp the cylinder block 7 in place against the frame or web 3.;

Referring now to Figs. 4 and 5 for a specific de scription of a second embodiment of my invention, there is illustrated a two-cylinder compressor 25, enclosed in a casing 26, the compressor cylinders being provided in a single compressor block 27, which is supported by a web or frame 28, which frame provides a bearing 30 for a shaft 29. Two eccentric devices 31 and 32 attached to the shaft, two connecting rods 33 and 34, two crank bearings 35 and 36, two pistons 3'7 and 38 and two cylinder heads 37a and 38a are assembled in essentially the same manner as above set forth with respect to the first embodiment of my invention.

The cylinder head adjusting means for the two cylinder compressor comprises dowel pins 39 and 40, disposed in a slot 41 in the cylinder block 27.

- Openings 42 and 43 in the frame 28 and eccentric bushings 44 and 45 provided with fingers 46 and 47, respectively, are provided in the same manneras described with respect to the first embodiment of the invention.

Bolts 48 are provided for clamping the cylinder block 27 to the carrying member 23 and apertures 49 for receiving the bolts 28 in the cylinder block 27 are slightly larger in diameter than the bolts 48. The bolts 48are threaded (not shown) into 'the carrying member 28.

In order to adjust the head clearance of the two cylinder compressor, bolts 48 are left loose or loosened, so that the cylinder block 2'7 is not clamped tightly to the web. The eccentric bushings-44 and 45 fitting the dowel pins 39 and 40 and the cylindrical openings 42 and 43 in the frame 28 are turned in order to move the cylinder structure toward or away from the shaft axis in order to obtain a desired clearance volume. One finger on each bushing, such as 460. and 47a, are then turned downwardly to prevent movement ofthe bushings. The bolts 48 are drawn up tightly to clamp the cylinder block 27 against the frame or web 28. The rotation of the eccentric bushings 44 and 45 move the cylinder block up and down and also sideways. Up and down movement is allowed for because of the enlarged apertures 49 for the bolts 48, and movement sideways is allowed for because the dowel *pins 39 and 40 may slide in the slot 41 in the cylinder' block. In view of the degree of accuracy with which parts of apparatus of this character are machined, the amount of adjustment ob'-.

tained on each cylinder by rotating the eccentric bushings. 44 and 45 is sufficient to obtain the correct clearance between the pistons and the cylinders.

From-the foregoing, it will be'apparent that I have provided a device for adjusting the head clearance of compressors without changing the stroke of the compressor piston or without the use of gaskets. It will also, be apparent that I have provided an adjustment which progressively varies the head clearance of a compressor by small amounts but which is capable of varying the clearance over a wide range depending upon the size of the eccentric bushing used. The adjusting device is obviomsly inexpensive tomanufacture and easy to operate as is seen from the foregoing description.

While I have shown my invention in two forms,

it will be obvious to those skilled in the art that.-

rocat'e in the cylinder, eccentric means rotatable about a fixed axis, means for connecting the piston and the eccentric means thereby providing the piston with a predetermined stroke, and supporting means for the cylinder including means.

foradjusting the distance between the cylinder head and the fixed axis of the eccentric means, said supporting means including a carrying member, a projection on said cylinder and a-housing in said carrying member into which the projection is disposed, and said adjusting means comprising an eccentric bushing surrounding said projection and fitting snugly and turnably between the pro jection and said housing.

2. A compressor comprising a cylinder, a head fixed to the cylinder, a piston arranged to reciprocate in the cylinder, eccentric means rotatable about a fixed axis, means for connecting the piston and the eccentric means-thereby providing the piston with apredeterinined stroke, and supporting means for the cylinder including means for adjusting the distance between the cylinder head and the fixed axis of the eccentric means, said supporting means including a carrying member, a projection on said cylinder and a housing in said carrying member into which the projection is disposed, and said adjusting means comprising an eccentric bushing surroundingsaid' projection and fitting snugly and tumably between the projection and said housing, and fur-.

ther supporting means including means for clamping said cylinder to said carrying member after the desired adjustment between the cylinder head and fixed axisof the eccentric means is made.

3. A compressor comprising a cylinder, a head fixed to the cylinder, a piston arranged to reciprocate in the cylinder, eccentric means rotatable about a fixed axis, means for connecting the piston and the eccentric means thereby providing the piston with a predetermined stroke, and. supporting means for the cylinder including means for'adjusting the distance between cylinder head and the fixed axis of the eccentric means, said supporting means including a carrying member, a projection on said cylinder and a housing in said carrying member into which the projection is disposed, and said adjusting means comprising an internally eccentric bushing surrounding said projection and fitting snugly and turnably between the projection and said housing, and means for fastening said adjusting means in place after the desired adjustment is made.

4. A compressor comprising a plurality of cylinders, a common cylinder block therefor, a piston arranged to reciprocate in each cylinder, eccentric means for each cylinder rotatable about fixed axes, means for connecting the pistons to their respective eccentric means and providing each piston with a predetermined stroke, and supporting means for each cylinder including means for adjusting the distance between each cylinder head and the fixed axes of its corre-' sponding eccentric means, said supporting means including a common carrying member, a number of projections on said cylinderblock and a number of housings in said carrying means both corresponding to the number of cylinders of the compressor, said projections adapted to be disposed in their corresponding housings, and said adjusting means comprising an internally eccentric bushing surrounding each projection and fitting snugly and turnably between each projection and its corresponding housing.

5. A compressor comprising a plurality of cylinders, a common cylinder block therefor, a piston arranged to reciprocate in each cylinder, eccentric means for each cylinder rotatable about fixed axes, means for connecting the pistons to their respective eccentric means and providing each piston with a predetermined stroke, and supporting means for each cylinder including means for adjusting the distance between each cylinder head and the fixed axes of its corresponding eccentric means, said supporting means including a common carrying member, a number of projections on said cylinder block and a number of housings in said carrying means both corresponding to the number of cylinders of the. compressor, said projections adapted to be disposed in their corresponding housings, and said adjusting means comprising an internally eccentric bushing surrounding each projection and fitting snugly and turnably between each projection and its corresponding housing, and means for clamping said cylinder block to said carry.-

ing means after the desired adjustment is made.

6. A compressor comprising a frame having a bearing, a shaft fitting the bearing and provided with an eccentric disposed beyond one end of the latter, a cylinder structure having a bore, a piston fitting the bore, means for transmitting motion from the eccentric to the piston, and means for anchoring the cylinder to the frame including clamping bolts carried by the frame and fitting cylinder structure openings sufliciently larger than the bolts to provide for ad-' justment of the cylinder structure toward and away from the shaft axis and means for moving the cylinder outwardly or inwardly with respect to the axis of said shaft in order to vary the clearance volume.

'7. A compressor comprising a framehaving a bearing and a cylindrical opening spaced from and arranged parallel to the bearing, a shaft fitting the bearing and provided with a crank pin disposed beyond one end of the latter, a cylinder, a piston fitting the cylinder, a rod for transmitting motion from the crank pin to the piston, a pin carried by the cylinder and disposed in said cylindrical opening, an eccentric bushing fitting said cylindrical opening and said pin, means providing for turning of the bushing to move the cylinder inwardly or outwardly with respect to the shaft axis in order to vary the clearance volume, means for holding the bushing in adjusted position, and means for clamping the cylinder to said frame.

8. A compressor comprising a frame having a bearing and a cylindrical opening arranged parallel to and spaced from the bearing, a shaft fitting said bearing and having a crank pin disposed beyond one end of the latter, a cylinder structure having a bore, a piston fitting the bore, a rod for transmitting motion from the crank pin to the piston, a pin provided on the cylinder structure and disposed in said cylindrical opening, an eccentric bushing fitting said cylindrical opening and said pin, means providing for angular adjustment of the bushing to move the cylinder structure inwardly or outwardly with respect to the shaft axis to vary the clearance volume, means for holding the bushing in adjusted position, and clamping bolts carried 'by 

